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And communicating between two Crazyradio is not yet possible, Crazyradio is not listening to the radio, only transmitting (there is a pull request for making it listen in the repos so it is comming though)

Has somebody made this possible in the meantime? I would be highly interested if I could enable communication between a PC and a Raspberry via crazyradio.

There is now a PRX mode in the Crazyradio firmware git repos, it should be what you need to communicate between two Crazyradios. Though I have not tested it personally so I am not sure of the state of it.

I just tested the PRX functionality in the latest commit and it works. If you compile the firmware from source, and use the prx and ptx examples from the crazyradio-firmware repos, you can communicate between two Crazyradios on two different computers